British Police Seek Suspected Ringleader of Bomb Attacks

British investigators have mounted a worldwide manhunt for the suspected bomb maker in the London attacks, a man seen on a videotape with four suspected bombers last Thursday morning at the Luton train station, an American official said Wednesday.

The four suspected bombers are seen leaving for a London-bound train, but the fifth man stays behind.

Investigators said the man is a British citizen, as were the four suspected bombers. While he is not "Anglo," said the American official, he is not of Pakistani descent. The official, who spoke on condition of anonymity so as not to upstage the British on a case the two countries are cooperating on, added that British police investigators know the man's name but decided not to release it or his image.

This fifth man is suspected of being the ringleader and possibly the bomb maker, the official said, in the attacks last Thursday in the London Underground and on a double-decker city bus that killed at least 52 people. Investigators described him as a highly trained person.

On Wednesday, several American law enforcement officials identified one of the suspected suicide bombers as a Jamaican-born British resident named Lindsey Germaine. The other suspected bombers were of Pakistani descent and lived in the gritty working-class neighborhoods of Leeds. [Page A13.]

Late Wednesday, the British police said officers had searched a home in Aylesbury, 40 miles northwest of London and close to Luton, but would not say whether anyone had been arrested.

The developments emerged as Charles Clarke, the British home secretary, offered the first official indication that British officials believed the four attackers were suicide bombers.

The attacks confronted Britons for the first time with a suicidal attack by British-born terrorists, apparently drawn from the ranks of disaffected Muslims and seeming to copycat attacks most Britons see only on their television screens from Israel or Iraq.

According to police accounts, the four men, aged between 18 and 30, gathered at King's Cross station at the heart of the London subway system and fanned out from there, detonating explosives on three subway trains and, almost one hour later, aboard a No. 30 bus.

One theory is that the men had aimed to strike at the four points of the compass on subway lines but were foiled by delays on a northbound line. The three Underground bombs exploded south, east and west of King's Cross.

"This is not an isolated criminal act we are dealing with," Prime Minister Tony Blair told Parliament. "It is an extreme and evil ideology whose roots lie in a perverted and poisonous misinterpretation of the religion of Islam."

Mr. Blair said his Labor Party planned to open negotiations with other parties on new antiterror laws.

"We will look urgently at how we strengthen the procedures to exclude people from entering the U.K. who may incite hatred or act contrary to the public good, and at how we deport such people, if they come here, more easily," Mr. Blair said.

Muslims and Christians alike have recoiled from the notion that the suspected bombers had emerged from the ranks of Britain's 1.6 million Muslims, who make up around 3 percent of the population.

"What we know now is appalling to contemplate," said Michael Howard, the leader of the Conservative opposition. "It will take us a long time to come to terms with the fact that these atrocities appear to have been committed by those who were born and brought up in our midst."

Mohammed Sarwar, a Muslim Labor member of Parliament, said, "We are deeply shocked that these are homegrown bombers, and the vast majority of the Muslim community condemn these barbaric attacks."

Investigators said authorities were concerned that despite Tuesday's raids on six homes in the Leeds area and the seizure of a car laden with explosives at Luton, some of the high-grade explosives used in the attack might still be unaccounted for. The police said Tuesday they had seized explosives from one of the homes in Leeds, and on Wednesday night, erected scaffolding and plastic sheeting around all six and refused to allow hundreds of residents to return to nearby buildings.

The investigators, who spoke in return for anonymity because they are not officially allowed to talk to reporters, said it was worrisome that the London bombers had gained access to such powerful explosives, possibly highly sophisticated plastic explosives from the Balkans.

Investigators were trying urgently to find out whether the bombers had contact with Al Qaeda operatives, possibly in North Africa.

Since the bombings, the police have given the impression that the attackers were what Mr. Clarke on Wednesday referred to as "foot soldiers," whose anonymity made it easier for them to slip through the net of the security services.

But after a meeting of European Union interior ministers in Brussels, Nicholas Sarkozy, the French ministry, said: "It seems that part of this team had been subject to partial arrest" in the spring of 2004. Mr. Clarke denied that any of the bombers had been arrested and released.

Mr. Sarkozy's aides scrambled later to say he had been referring to arrests among the broader Islamic movement, not the London bombers.

Before the meeting, Mr. Clarke said European nations had to defend their values of society "against those who would destroy it."

Without using the term "suicide bombing," he said: "That means standing out against, in a very strong way, anybody who preaches the kind of fundamentalism, as I say, that can lead four young men to blow themselves and others up on the tube on a Thursday morning.

"We have got to root out those elements from within our community that want to destroy it. That puts different burdens on all of us.

"We have to understand that these foot soldiers who have done this are only one element of an organization that is bringing about this kind of mayhem in our society.

"And we have to attack the people who are driving it, organizing it, manipulating those people," he said.

Pakistan's interior minister, Aftab Ahmed Khan Sheparo, said Wednesday that his country had given "information" to Britain about a possible attack before the British elections in May, but did not elaborate.

With government ministers warning that more attackers may still be at large, many Britons have shown themselves stoic, despite a rash of security scares across the capital as police investigate apparently suspicious packages.

"I'd rather catch a bus than a tube now unless I'm in a desperate hurry," said David Ellis, 45, an office worker awaiting a subway train at St. James's Park station. "Probably before long I will have forgotten about it. It sounds dreadful, but you just get on with life."

In radio talk shows and in e-mail messages to television stations, Britons seemed puzzled - and annoyed - about the causes of the attack. Some expressed frustration with the government's close alliance with the United States in its campaign against terrorism, which has led to two wars.

"We've got to look at the reasoning behind these things," said Saraj Qazi, a 25-year-old Muslim boutique owner in Luton, just north of London, where police suspect the bombers gathered for their final brief journey into the British capital on July 7.

"There's no denying it's payback for what's happened in Iraq and Afghanistan," he said. "You've been bombing people for the last two to four years, so you are going to get a backlash."

"England is a great country and we love it to bits but do we love this government? No," Mr. Qazi said. "There were 24 Muslims killed in Iraq today; there will be more tonight and more tomorrow."

The identification of the attackers as British-born Muslims has deepened the anxieties of Muslim leaders that they will face a backlash. There have already been incidents of mosques being attacked.

Mr. Blair, who met with Muslim legislators on Wednesday, promised immediate discussions with Muslim leaders to "debate the right way forward."

But, referring to Islamic extremism, he said, "In the end this can only be taken on and defeated by the community itself."

In Parliament, Shahid Malik, a Labor legislator from the same West Yorkshire area that was home to the bombers, said condemnation of extremists was "not enough and British Muslims must, and I believe, are prepared to, confront the voices of evil head on."

The notion of more draconian anti-terror laws has raised concerns that Britain will forfeit its long-standing commitment to tolerance and civil rights in the name of a war on terror modeled on that of the United States.

But Mr. Clarke, the home secretary, argued that civil rights had to be balanced against the needs of security.

"I argue that it is a fundamental civil liberty of people in Europe to be able to go to work on their transport system in the morning without being blown up or subjected to terrorist attack or to conduct their lives without being at risk of serious and organized crime," he said. "The question of civil liberties has to be treated in a proportionate way."